[Xperia Z2 Tablet Android Development] Diewi:
MultiROM is a one-of-a-kind multi-boot mod. It can boot any Android ROM as well as other systems like Ubuntu Touch, once they are ported to that device. Besides booting from device's internal memory, MultiROM can boot from USB drive connected to the device via OTG cable. The main part of MultiROM is a boot manager, which appears every time your device starts and lets you choose ROM to boot. You can see how it looks on the left image below and in gallery. ROMs are installed and managed via modified TWRP recovery. You can use standard ZIP files to install secondary Android ROMs and MultiROM even has its own installer system, which can be used to ship other Linux-based systems.

Features:

* Multiboot any number of Android ROMs

* Restore nandroid backup as secondary ROM

* Boot from USB drive attached via OTG cable

You can also watch a video which shows it in action.​

WARNING

It is dangerous. This whole thing is basically one giant hack - none of these systems are made with multibooting in mind. It is no longer messing with data partition or boot sector, but it is possible that something goes wrong and you will have to flash factory images again. Make backups. Always.​

IMPORTANT

I'm not responsible for anything, you do all this on your own risk.

Once you have flashed and set up MultiROM, don't flash another boot.img using fastboot or normally. Always go to "Advanced -> MultiROM" to flash ROMs/kernels or other mods.

If you want to uninstall MultiROM, just flash the MultiROM uninstaller.

I am not certainly sure about the compatibility with stock Roms, I still need to test this yet.

Your device must not be encrypted.

To all devs maintaing Stock-based ROMs: Feel free to use my patched stock kernels to add MultiROM support to your ROMs.

When booting another ROM, you'll notice that in some cases, you can enter the recovery of the boot.img of the ROM. Please don't use it, flash everything using MultiROM TWRP.

INSTALLATION

Before installing MultiROM, make sure that your device is running a kernel that implements the so-called hardboot patch. Below is an (incomplete) list of these kernels. If your current kernel does not support hardbooting, flash one of these kernels that support your ROM.

NOTE:Currently, the only supported kernel is the M5-Kernel which is CM-based. Hence, only CM-based ROMs work for now until other kernels implement the harboot patches.

Download the MultiROM Manager application and launch it. This application will check again if your current kernel supports hardbooting. Please, DO NOT proceed if the application validates your kernel.

Press the "Install" button and let your device reboot into recovery to complete the installation.

That's it. You can now go to "Advanced -> MultiROM" to start flashing other ROMs.

SUPPORTED KERNELs

Here is an incomplete list of kernels that implement the harboot patch for the Z2 tablet:

M5-Kernel

Adding ROMs

Go to recovery, select Advanced -> MultiROM -> Add ROM. Select the ROM's zip file and confirm.​

Using USB drive

During installation, recovery lets you select install location. Plug in the USB drive, wait a while and press "refresh" so that it shows partitions on the USB drive. You just select the location (extX, NTFS and FAT32 partitions are supported) and proceed with the installation.

If you wanna use other than default FAT32 partition, just format it in PC. If you don't know how/don't know where to find out how, you probably should not try installing MultiROM.

If you are installing to NTFS or FAT32 partition, recovery asks you to set image size for all the partitions - this cannot be easilly changed afterward, so choose carefully. FAT32 is limited to maximum of 4095MB per image - it is limitation of the filesystem, I can do nothing about that.

Installation to USB drives takes a bit longer, because the flash drive is (usually) slower and it needs to create the images, so installation of Ubuntu to 4Gb image on my pretty fast USB drive takes about 20 minutes.

Enumerating USB drive can take a while in MultiROM menu, so when you press the "USB" button in MultiROM, wait a while (max. 30-45s) until it searches the USB drive. It does it by itself, no need to press something, just wait.​

Updating/changing ROMs

1. Primary ROM (Internal)

Flash ROM's ZIP file as usual, do factory reset if needed (it won't erase secondary ROMs)

Go to "MultiROM menu" (Top right corner in the recovery) in recovery and do Inject curr. boot sector. if it is not done directly during installation of the Rom.

2. Secondary Android ROMs

If you want to change the ROM, delete it and add new one. To update ROM, follow these steps:

Go to "MultiROM menu" (Top right corner in the recovery) -> List ROMs and select the ROM you want to update.

Select "Flash ZIP" and flash ROM's ZIP file.

Using stock as primary / Installing MultiRom on stock

Applies only if don't run a custom kernel that supports loading the recovery from the FOTAKernel partition.

Install the multirom recovery (e.g. via the app).

Shutdown the device and get into the bootloader mode (VolUp + connect the USB cable attached to your PC which must have a functional fastboot/adb installation).

Boot a kernel that supports booting the recovery from the FOTAKernel partition. For instance, you can extract the boot.img file from the AOSP installation zip and flash it with "fastboot boot boot.img" in the directory where you extracted the boot.img file.

During boot hit the VolumeUp key as soon as the led shows a purple light. An orange light indicates that booting into recovery has successfully been triggered.

Install the multirom.zip from the Downloads folder.

Add secondary roms to your liking.

To re-access the multirom recovery, the above steps must repeated except the installation of the multirom.zip file.

Install a stock rom as secondary

This only works if you are using MultiRom version 33c or larger (excluding 33x-z).

1. Existing primary stock rom

Use these instructions if you plan to move an existing stock rom installed as primary. This guide assumes that multirom recovery is properly installed.

Shutdown the device.

Boot a kernel that supports booting the recovery from the FOTAKernel partition. For instance, you can extract the boot.img file from the AOSP installation zip and flash it with "fastboot boot boot.img" in the directory where you extracted the boot.img file.

During boot hit the VolumeUp key as soon as the led shows a purple light. An orange light indicates that booting into recovery has successfully been triggered.

MAKE A BACKUP!

Go to "MultiROM menu" (Top right corner in the recovery) in recovery and tap "Swap roms".

Select the option "Copy primary rom to secondary/internal" and start the operation.

Wait until the operation finishes and flash your desired rom. (Alternatively you can also use any secondary rom to be the primary rom using the "Swap option" mentioned above.

Reboot.

2. Fresh stock installation

Use these instructions if you do not have a stock rom installed as primary. This guide assumes that multirom recovery is properly installed.

Shutdown the device.

Boot a kernel that supports booting the recovery from the FOTAKernel partition. For instance, you can extract the boot.img file from the AOSP installation zip and flash it with "fastboot boot boot.img" in the directory where you extracted the boot.img file.

During boot hit the VolumeUp key as soon as the led shows a purple light. An orange light indicates that booting into recovery has successfully been triggered.

MAKE A BACKUP!

Install the stock rom via an install zip of via an FTF. NOTE: For the FTF method you need to shutdown the device and boot into download mode (VolDown pressed while connecting the USB cable; cable connected to the PC). Use for instance flashtool to flash ONLY the kernel, system, and cache image. In addition, you MUST select "Wipe apps_log"!

When the device reboots, let it boot up and finish the first time setup procedure.

Shutdown the device.

Start the device into multirom recovery (VolDown + Power).

Go to "MultiROM menu" (Top right corner in the recovery) in recovery and tap "Swap roms".

Select the option "Copy primary rom to secondary/internal" and start the operation.

Wait until the operation finishes and flash your desired rom. (Alternatively you can also use any secondary rom to be the primary rom using the "Swap option" mentioned above.

Reboot.

SOURCEs

MultiROM - https://github.com/XperiaMultiROM/multirom/ (branch master)

Modified TWRP - https://github.com/XperiaMultiROM/android_bootable_recovery (branch master)

Kernel w/ kexec-hardboot patch - https://github.com/Myself5/android_kernel_sony_msm8974/ (M5-Kernel)​

FAQs can be found here.

CHANGELOGs

LTE-Version:

Multirom

Multirom recovery

WIFI-Version:

Multirom

Multirom recovery

CREDITs

Tasssadar

Myself5

Olivier

Garcia98

Thunder07

skin1980

Envious_Data

[NUT]

AndroPlus

Panic Brothers

You might want to consider a Donation to Tasssadar, who is the Mastermind behind all of this.

​

Also, you might consider a donation to Myself5 since he did the port for devices based on the shinano board.

Thanks a lot to those who have donated!​

XDA:DevDB Information

MultiROM for Sony Xperia Z2 Tablet, Tool/Utility for the Sony Xperia Z2 Tablet

Contributors

Diewi, Myself5

Source Code: https://github.com/XperiaMultiROM/multirom/tree/master

Version Information

Status: Testing

Created 2016-02-08

Last Updated 2017-01-08